Starting engine & generator on a covered DP

[jstdreamin]

I have an '08 Pacifica that I have covered with an Alco dlx cover. I want to fire up the engine and generator to "Exercise" them but don't want to completely remove the cover. I realize that I probably won't be able to run the AC units with the cover on and I'm planning to remove the straps and raise the cover above the radiator on the back of the coach so the radiator can get air as well as raisin the cover from areas around the exhaust pipes. Any other areas I should be mindful of so I don't ruin my cover or either engine? Also, if the temp is in the low 30's how long should I run the block heater before starting?

[Ray,IN]

DO NOT start the drive engine to "exercise" it! You do more harm than good doing so, as a diesel engine will never reach normal operating temperature while idling, especially in cold weather. This creates condensation in the crankcase, cylinder damage from washing oil from cylinder walls by unburned fuel. In fact, a diesel engine already at normal operating temperature, WILL cool down while idling. The genset OTOH does require monthly operation at 1/2 or more load for at least 30 minutes to dry out condensation from the windings.

[KennyGolub]

Originally Posted by Ray,IN

DO NOT start the drive engine to "exercise" it! You do more harm than good doing so, as a diesel engine will never reach normal operating temperature while idling, especially in cold weather. This creates condensation in the crankcase, cylinder damage from washing oil from cylinder walls by unburned fuel. In fact, a diesel engine already at normal operating temperature, WILL cool down while idling. The genset OTOH does require monthly operation at 1/2 or more load for at least 30 minutes to dry out condensation from the windings.

X2 ..... I do however run the generator and put a load on it every two weeks.

To me, that is the down side of having a cover. Too much to take it off and drive around with the coach for a while. I keep going back and forth on whether or not to use it. But my campers always look so nice when I remove the cover in the spring.

[BFlinn181]

Ray was correct, the engine won't reach full temperature at idle. If you start it anyway, check for where your engine air intake is. If this 'mini grill' is blocked by the cover, if you're lucky just the cover will damaged, if you're not it could collapse part of the air intake system components pulling a strong suction. To exersize the generator, plug in a space heater or two to give the generator something to do. Make sure the generator exhaust is uncovered and try to plug the heater(s) into an outlet that isn't protected by a GFI.

[Wizard]

To exercise the generator, run the microwave instead of the ac units

[D Lindy]

I have to wonder who or when the need to exercise the generator to dry out the windings came about. Having served 20+ years in the military and 6 of those as a Power Generation Mechanic there was never anything in any of our military Technical Manuals, Periodic Maintenance instructions etc about exercising our generators.

[palehorse89]

Originally Posted by D Lindy

I have to wonder who or when the need to exercise the generator to dry out the windings came about. Having served 20+ years in the military and 6 of those as a Power Generation Mechanic there was never anything in any of our military Technical Manuals, Periodic Maintenance instructions etc about exercising our generators.

The "Bible" that comes with these RVs says to........
I have never read to as a failure occurred do to moisture from not runing one......

[dennis45]

Originally Posted by D Lindy

I have to wonder who or when the need to exercise the generator to dry out the windings came about. Having served 20+ years in the military and 6 of those as a Power Generation Mechanic there was never anything in any of our military Technical Manuals, Periodic Maintenance instructions etc about exercising our generators.

I'll second that motion. IMHO, this is one of those Urban Legends we hear about. I think this is born from Emergency Stand-by generators that have to be exercised monthly by building codes.

[jstdreamin]

Great advice folks! Thanks!

[Hoffie]

I purchased a 1997 Pace Arrow in 2011 that had an Onan 5500 that only had 102 hours on it. I ran the generator for a couple of weekend trips and put about 60 hours on it. The third time I started the generator, it would not produce any electricity. The Onan repair man informed me that the rotor and stator were very rusty and had fried the voltage regulator. After the repairs were made, he told me that these generators were made to be used (he has seen units with over 10,000 hours still in service) and not just set for months, years not being used. He told me to make sure I ran the generator under load for 2 or 3 hours a month at a minimum. It may be an urban legend but I am going to burn a little fuel every month in mine.

[sirpurrcival]

I attended an Onan seminar once on generator usage and maintenance where that mantra was repeated as well about "use it or lose it". However, I'm not sure that sitting a few months over the winter equates with years and years of non use, especially in a non-humid region. 102 hours over 14 years means that it basically was never used at all and perhaps sat for several years without ever being run. I think you could reasonably expect any engine that hasn't run for years to not be good to go after sitting for that long. I don't use my generator for much but I do exercise it periodically but over the winter, it doesn't get a religious monthly run. If I get it going for an hour or so over a 4 month span, that is about it. I haven't seen any issues so far.

[Gerryl]

I have a gas coach and generator. At the end of the season, I filled the tank and put in the correct amount of Sta-bil in. I am the second owner and when I bought the MH the owner was proud to tell me that there was only 60 hours on the gen. I of course thought this was a good thing until I had a problem shortly after I bought it. It cost me about $700 to fix the generator.
For over 20 years I was a serious snowmobiler and learned that the best way to store my sled was to use Sta-bil and start it every month.

[KennyGolub]

Warranty is another thing to consider.

While under warranty, they want it run two hours a month. I've been told by my local RV Center, that they have serviced generators that were under warranty and did not meet that requirement. They told me the Onan out right denied the claim because of that.

I haven't heard that said anywhere else, but I don't know why he would say that. In my manual with my new (2015) Onan, it does say to run it at least two hours per month.